Composition for coating stench-sheets



S. W. FUERTH.

COMPOSITION FOR COATING STENQIL SHEETS.

APPLlCATION FILED NOV- ao. 1915.

1, 1 96,098 Patented Aug. 29, 1916.

IN V EN TOR:

W 1 TN ESS ES:

UNITED STATES PATENT oFFicE.

SYDNEY W. FUER TH, OF NEWAB K, NEW JERSEY, ASSIGNOR T HIMSELF AN D GUSTAVE W. FUEBTH, OF NEWARK, NEW JERSEY.

COMPOSITION FOR COATING STENCIL-SHEEQS.

To all whom it may concern:

Be it known that" I, SYDNEY W. a citizen of the United States, resldlng in Newark, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Compositions for Coating Stencil-Sheets, of which the following is a specification.

This invention relates primarily to stencil sheets of the kind in which a stencil is prepared by the use of a typewriting machine or a stylus, the stencil sheet being usually made of Yoshino or other tissue paper, whlch has usually been coated with eitherwax or gelatin, such coating being displaceableby the types of the typewriting machine, but impermeable to the stenciling 1nk, which however passes readily through the places whlch have been struck by the types, whereby many copies may be made by the usual stenc lcopying or duplicating machine. Typewritten stencils of this character are also used in addressing machines, etc.

In British patent to De Zuccato, 13,85l'of 1893, there is disclosed a tissue base coated with glue or gelatin rendered ins'oluble by means of ordinary fixing or hardening agents, whereby the sheet is rendered dura-.

ble and not liable to become injured, as is the case with an ordinary wax sheet. It has usually been the practice to soften the -De Zuccato glue or gelatin sheets to enable cato patent is of the character of glycerin,

which had the advantage of not drying rap.- idly, and which acted upon the glue or gelatin to render the sheet soft enough to yield to the type impressions, without making it too soft to prohibit its subsequent use in making stencil copies. It is customary in some cases not to soften the coating until the operator is ready to write the stencil.

The main object of the present invention is to produce a sheet which shall not rapidly wear out, as does the ordinary wax sheet, and which, even if not quite so proof as the De Zuccato' sheet againstinjury from violent handling, shall be nevertheless adapted to stand a reasonable amount of rough usage without liability to crack or receive other injury, and which can be supplied to the market ready for use, so that the operator shall not be burdened with the task of mois- Specification of l atent.

Patented Aug. 29, 1916..

Application filed November 30, 1915. Serial No. 64,375.

tening each sheet preparatory to typewriting or otherwise cutting the stencil, and to produce a stencil sheet which, although soft enough toyield to the blows of the-typewriter types, is still durable enough to stand along run in the stencil-copying or duplicating machine, and which, moreover, although soft as aforesaid, is not liable to deteriorar tlon from age. By this invention the annoyance experienced by the operator .in using a sheet which must be first moistened, (such as injury to the .typewriting'machine by rust,

corrosion, etc, and the-filling up of the types with sticky matter from the .moist stencil sheet), may be avoided, since the operator. mayplace his-stencil directly in the typewrltmg machine, without any preliminary softening, and as soon as the stencil is written, may at once place it in the duplicating me e and proceed to make the stencil copies. It is unnecessary, after the stencil is written, to subject the sheet to a drying or 'shrmkmg operation, to widen the typewntten characters thereon in order to permit free passage of ink therethrough.

My Improved stencil sheet, while perhaps not so proof against cracking under violent handling as is the aforesaid softened glue or gelatin sheet of the De Zuccato. patent, is SCI ll very much less liable to crack-or become injured than is the ordinary wax stencil sheet (cracks being objectionable because they are permeable by the stenciling ink).

Again, the wax sheet (which is susceptible to 'melting at comparatively low temperature) becomes somewhat heated in the, operation of printing the stencils therefrom, and the heat tends to melt the wax, with the result that a minute quantity of the waxis deposited by the sheet when each stencil copy is made, so that in a relatively short period the wax stencil sheet becomes worn out. This difficulty is overcome by my improved 7 sheet, which although not glue or gelatin,

is still highly flexible and limp, and while sulfieiently plastic, is not affected by even tropical temperatures; being capable of withstanding 130 degrees Fahrenheit, or even higher heat, without deterioration. Moreover, the sheet is still capable of being cleaned after use, when it is'ready for repeated use in the stencil-copying machine.

Experience shows that many hundred copies may be produced from a stencil without showing any deterioration. The improved sheet is capable of making several times as many stencil copies as is a wax sheet, and either water ink or oil ink may be used.

Other features and advantages will hereinafter appear.

not only has a softening effect for rendering the sheet limp and plastic, but also has the quality of preserving the softness, pli- The accompanying sheet of drawings' hardening agent, as is the case with glue or gelatin. The seed-lac or the original lac may be otherwise prepared than by making it into shellac. This shellac is used in the form of a varnish, and this may be what is commercially known as white shellac varnish, which averages about six pounds of shellac to one gallon of suitable spirit. Shellac varnish is generally prepared by dissolving a quantity of shellac in grain alcohol, which is denatured only to an extent of about five per cent; then the solution is redissolved in a poorer grade of alcohol. The varnish has the requisite strength and durability, and yet it can be given the desired flexibility; and my invention includes shellac or any equivalent naturally hard or impermeable varnish that is sus ceptible of being shortened and softened or made pliable in the process of its manufacture, while retaining the proper tensile strength and long-wearing quality. The

abilityand plasticity; the sheet is hygroscopic and long-lived. A variation of the quantity of glycerin used may vary the length of life of the sheet to a certaln'extent. One reason for the long life of the sheet is because the shellac or lac, not being in the nature of an animal substance, but being resinous, is not. so liable to decompose from the action of the glycerin thereon.

'One of the main features of my invention' is coating a Yoshinosheet with shellac varnish which is softened for use as a stencil.-

In some cases, castoroil may be employed instead of glycerin; but I prefer theglycerin in most instances, because it mixes with the alcohol, hereinafter mentioned, and

has a good softening effect, and the finished 'sheets do not become brittle, nor does the shellac is of a permanent nature and not' liable to deteriorate with age, and is therefore superior to glue and gelatin, which being of animal origin are subject to slow decomposition, unless precautions are taken. The shellac varnish renders the coating impervious to ink; and this varnish naturally hard, is softened by other material used in the coating, to such an extent that it may give wayor be driven out by theblows of the types'of the typewriter, to permit the ready passage of ink through the type perforations.

To the end that the coated'sheet shall exhibit softness, I preferably employ a crude glycerin, which may be soap lye crude glycerin. This is a salty glycerin, produced by the first of a series of distillates which occur in the process of making soap. This first disti'llate contains a part of the salt with which the soap fat was cooked, and is a cheap variety of glycerin. The invention, however, is not limited to the use of this precise variety. The soap lye crude glycerin is .preferred because it will mix more readil than other grades of glycerin; and this 0 aracteristic I ascribe partly to its alkaline nature, which forms a soap with the oleic acid hereinafter mentioned. The glycerin glycerin leave a copies.

Another ingredient of the coating is alcohol, which acts as a vehicle to aid in thoroughly mixing the'shellac varnish with the glycerin, etc.; and the alcohol may also be deposit upon the stencil v varied in quantity to meet requirements that I .may arise as to thickness of thecoated sheet,

density of the coating, etc. The alcohol is preferably denaturedor Woodalcohol. Al-

cohol diminishes the denseness of the coat ing and affects the Weight thereof. All, or a substantial part of the alcohol, evaporates within a very few minutes from the freshly coated sheet, and the sheet is ready for use within an hour from the time it is manufactured, because of such rapid evaporation, thus giving an advantage over the manufacture of glue and gelatin coated sheets in which the glue is mixed with water, so that the sheet is very much longer in drying.

I also employ oleic acid or the like. This might be used in the form of oleic soap. The oleic acid is of value in mixing together the varnish, the glycerin and the alcohol, and it serves to shorten the varnish, so that the coating will be friable, or readily'displaceable by the type blows thereon. Commercial bleached oleic acid may be employed," this being the ordinary unrefined type; but, if desired, it is permissible to use refined oleic acid; and, as already stated, this ingredient can be used in a variety of forms.

The oleic acid mixed with the glycerin forms a fairly thick mixture of about the density of light molasses; and this diluted withalcohol prepares it for its reception in the varnish. The oleic acid not only shortens the shellac varnish, or renders it friable, but also destroys the natural tackiness or adhesiveness of the varnish. It has also theimportant function of incorporating, or uniting the glycerin with the shellaccontained in the varnish. The soap lye crude glycerin, as alreadyexplained, mixes more readily than other grades of glycerin, this probably being due to its alkaline nature, so that it presumably forms a'soap with oleic acid. The alcohol serves as a vehicle toaid in thoroughly mixing together the oleic glycerin mixture and the shellac varnish.

In preparing the coating the following formula may e employed, but it may be considerably varied in accordance with the requirements, andthe proportions given do not need to be exactly followed: white shellac varnish 46%, commercial-bleached oleic acid 18%, soap lye crude glycerin 18%, denatured or Wood alcohol 18%. The above 7 proportions are by volume.

When uncolored, the stencil sheet has the appearance and color of an ordinary wax stencil sheet, but if desired, coloring matter or dye in suflicient quantity may be added to the coating mixture or composition; and the oleic acid may act as a solvent for the dye. i

To 20 ounces of commercial bleached oleic acid may be added 20 ounces of soap lye crude glycerin. These may be thoroughly incorporated. The resulting mixture may then be slowly stirred into 20 ounces of denatured alcohol; the resultant being a clear amber colored mixture. 7 This may be mixed in the presence of heat (supplied by a water bath) with 50 ounces of white shellac varnish. The temperature should be maintained at about 44 degrees centigrade. The

strength of the solutions and proportions of the ingredients may be otherwise varied by those skilled in the art; and a coating of any desired thickness may be obtained; and it is also obvious that equivalent substances may be substituted. The preparation may then be placed in a sheet-coating pan kept heated by a water bath at a temperature between 40 and 44 degrees Centigrade by water circulation; and the sheets may be coated by the use of a revolving roller, the lower part of which is immersed in the preparation, the sheet being drawn across or along the upper part of the roller, and receiving its coating from the liquid that rises .up on the roller; this operation being like that which is followed-in coating wax stencil sheets. Or the sheet may be coated in any other suitable manner.

The foregoing process produces a Yoshino or other tissue coated stencil sheet, which is about from two-one-thousandths to fourone-thousandths of an inch in thickness. The thinner sheets are useful in preparing typewriter stencils on typewriting machines having shallow types. The stencil sheet has a practically .unwearable, hard surface, this surface being upon the uncoated side of the sheet; that is, upon the side of the with the copy-sheets or work-sheets during the operation of stenciling upon the latter.

The distinction between the coated and uncoated sides of the stencil sheet is not great, because the coating permeates the sheet thoroughly. 7

In typewriting the stencil, I employ a tissue sheet A to cover the stencil sheet B, and later being backed with a Yoshino or other porous tissue sheet C, into which the coating of the stencil sheet is forced by the types of the typewriter. I also preferably employ a backing sheet 1) having a hard surface. The front sheet A is not essential in all cases. I

The stencil is ready for typewriting' as soon as the sheet is coated and dry; and it remains in this always-ready condition for a great length of time, and may therefore be regarded as being permanently in final condition for typewriting, without being apt to deteriorate because of the presence of the shortening and softening elements in the coating.

The stencil sheet is impermeable to stenciling ink, so that great numbers of copies may be produced from a single stencil, and either water ink or oil ink may be used. Moreover, the stencil may then be cleaned for subsequent use, by the use of any suitable substance, such as that commonly used in thinning inks, or washing ink from printing presses, or other cleaner.

Variations may be resorted to within the scope of the invention, and portions of the improvements may be used without others.

Having thus described my invention, I claim:

1. A composition for coating stencil sheets, comprising as its principal ingredient an alcohol solution of a preparation of lac, and also comprising ingredients for sof tening, shortening and binding.

2. A composition for coating stencil sheets, comprising as its principal ingredicut a preparation of lac in a state of dissolution, and also comprising ingredients for softening, shortening and binding.

3. A composition for coating stencil sheets, comprising a solution of lac in alcohol, and comprising glycerin as a softening agent, and also comprising means for shortening and binding.

4. A composition for coating stencil sheets, comprising a solution of lac in alcohol, and comprising glycerin as a softening agent, and also comprising oleic acid for shortening the lac and to serve as a binder for the composition.

5. A composition for coating stencil sheets, comprising a solution of lac in alcohol, and comprising glycerin as a softening and softened and made hygroscopic.

7. A composition for coating stencil sheets, comprising shellac varnish, soap lye crude glycerin, denatured alcohol, and oleic acid, substantially as set forth.

8. A composition for coating stencil sheets, comprising the following ingredients in about the proportions given by volume: shellac varnish 46%, oleic acid 18%, soap lye crude glycerin 18%, denatured alcohoT 9. A preparation for coating stencil sheets, comprising as its principal ingredient a varnish, and also' comprising a solvent, a softening agent, and means for shortening and binding; said composition, in its final condition on the sheet, having such plasticity as to be displaceable by the types of the typewriter.

10. A preparation for coating stencil sheets, comprising a resinous varnish, a hygroscopic substance for softening the varnish, and means for shortening the varnish. 11. A preparation for coating stencil sheets, comprising a varnish, a substance for softening the varnish, a dye, and means for shortening the varnish and dissolving the dye and binding the preparation.

12. A composition for coating stencil sheets, comprising shellac, crude glycerin, a

solvent, and a shortening agent.

13. A composition for coating stencil sheets, comprising shellac, crude glycerin, a solvent, and means for shortening and bind- 1n %4. A composition for coating stencil sheets, comprising shellac, crude glycerin, a solvent, means forshortening-and binding, and a die.

15. A composition for coating stencil 7 sheets, comprising oleic acid, a resinous preparation shortened by the oleic acid, a solvent, and means for softening the coated sheet. 7

16. A composition for coating tissue stencil sheets, comprising as its principal ingredient a resinous varnish and also comprising means for shortening and softening the varnish and depriving it of its natural tackiness; said composition, in its final condition on the sheet, having such plasticity as to be displaceable by the types of the typewriter.

17. A composition for coating tissue sheets for stencil purposes, comprising a preparation of lac, a preparation of glycerin to soften the lac, and means for uniting theglycerin with the lac preparation and shortening the lac.

18. Acomposition for coating tissue stencil sheets, comprisin as its principal ingrc dient shellac varnis and also comprising a preparation of glycerin to soften the same, and means to unite the g1 cerin with the varnish; said composition, in its final condition on the sheet, having such plasticity as to be displaceable by the types of the typewriter.

19. A wear-resisting hygroscopic preparation of lac softened by crude glycerin and shortened by oleic acid and dyed.

20. A wear-resistin hygroscoplc prepa-' ration of lac softened by crude glycerin and shortened by oleic acid to an extent to be. displaceable by the action of typewriter types thereon.

21. A wear-resisting hygroscopic flexible hard preparation of lac permanently softened by crude glycerin and shortened by oleic acid.

22. A wear-resisting but limp and hygroscopic preparation of an impermeable varnish which is shortened and softened.

23. A wear-resisting but limppreparation of shellac varnish softened by a hygroscopic substance and shortened.

24. A wear-resisting but limp reparation of shellac varnish softened by a ygroscopic substance and shortened with olelc acid.

25. A wear-resisting but limp preparation of resinous varnish permanently softened by a glycerin preparation and shortened.

A wear-resisting limp preparation of shellac shortened with oleic acid and permanently softened and rendered hygroscopic by soap lye crude glycerin.

SYDNEY W. FUERTH.

Witnesses:

C. NEWELL, E. B. LIBBEY. 

